Mr Hilliam admits having taken human remains from the Poutō foreshore but said they came from hāngī pits, not Māori burial grounds.

That's caught the attention of Heritage New Zealand, which is now investigating.

Senior archaeologist Frank van der Heijgden said it was a criminal offence to damage an archeological site, and carried a potential penalty of $60,000.

Mr Hilliam said he was forced to take the remains, because no one would issue him a permit.

"I got sick and tired of the system and this is why I went ahead. I wanted to know the origin of these people."

An article on Mr Hiliam's theory, published in the Northern Advocate, has been removed from the paper's website. Editor Craig Cooper issued an apology; he admits they didn't check the source and regrets the story had been a catalyst for some people to infer political or racial motives.

Mr Cooper said in his apology that Northlanders - and New Zealanders - should be open to debate about the past, the present and the future. But he said there was a right way to encourage any such debate, and they did it the wrong way.

Mr Hilliam was disappointed in Mr Cooper's apology, and said there was too much political correctness.

He declined to reveal the name of the forensic pathologist in Edinburgh he said he consulted, and said the person had since passed away. RNZ also asked to speak to someone at Edinburgh University, but Mr Hilliam said his contact was a freelancer.

Local kaumātua Ben de Thierry said he was shocked by Mr Hilliam's claims, and supported the investigation by Heritage New Zealand.

Mr van der Heijden said if a member of the public came across human remains they should call authorities.

"What people really should do if human remains are discovered, they need to be covered up if possible and reported to local police, Heritage NZ and tangata whenua as well, and they can assist with the ... appropriate removal according to their tikanga."